Commercial lunar propellant architecture: A collaborative study of lunar propellant production

Aside2Section Authors: Gordon Roesler, Robots in Space LLC, President; and David Kornuta, United Launch Alliance, CisLunar Project Lead.2 from Earth, the inner solar system is like a vast desert where water and other volatiles are scarce. An old saying is, “In the desert, gold is useless and water is priceless.” While water is common on Earth, it is of very high value in space. Science missions to the Moon have provided direct evidence that regions near the lunar poles, which are permanently in shadow, contain substantial concentrations of water ice. On the lunar surface, water itself is critical for human consumption and radiation shielding, but water can also be decomposed into hydrogen and oxygen via electrolysis. The oxygen thus produced can be used for life support, and hydrogen and oxygen can be combusted for rocket propulsion. Due to the Moon’s shallow gravity well, its water-derived products can be exported to fuel entirely new economic opportunities in space. This paper is the result of an examination by industry, government, and academic experts of the approach, challenges, and payoffs of a private business that harvests and processes lunar ice as the foundation of a lunar, cislunar (between the Earth and the Moon), and Earth-orbiting economy. A key assumption of this analysis is that all work—construction, operation, transport, maintenance and repair—is done by robotic systems. No human presence is required. Obtaining more data on conditions within the shadowed regions is vital to the design of a lunar ice processing plant. How much water is actually present, and at what percentage in the lunar regolith? How firm or soft are the crater bottoms, and how will that affect surface transportation? How deep is the ice resource, and in what state is it deposited amongst the regolith? These and other questions must be answered by precursor prospecting and science missions. A wide range of potential customers for the hydrogen and oxygen products has been identified. They can be used to fuel reusable landers going back and forth between the lunar surface and lunar orbit. They can make travel to Mars less expensive if the interplanetary vehicle can be refueled in cislunar space prior to departure. Operations closer to Earth can also benefit from this new, inexpensive source of propellant. Refueling in Low Earth Orbit can greatly improve the size, type, and cost of missions to Geosynchronous Earth Orbit and beyond. This study has identified a near term annu